- ID:
- ivo://CDS.VizieR/II/354
- Title:
- HIP and TGAS stars reddening and extinction
- Short Name:
- II/354
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- These reddening and interstellar extinction estimates are a result of a series of studies presented in the papers 2009AstL...35..780G, 2010AstL...36..584G, 2012AstL...38...12G, 2012AstL...38...87G, 2017AstL...43..472G and finally 2017MNRAS.472.3805G and 2018MNRAS.475.1121G. The key basis of these estimates is the 3D reddening map of Gontcharov (2017AstL...43..472G, 2017PAZh...43..521G, Cat. J/PAZh/43/521). This map has been tested among eight sources of reddening and extinction estimates for nearly 60,000 Gaia DR1 TGAS main sequence stars younger than 3Gyr with a relative error of the Gaia parallax less than 0.1. The sources are tested in their ability to put the stars among the PARSEC and MIST theoretical isochrones in the Hertzsprung-Russell diagram based on the precise Gaia, Tycho-2, 2MASS and WISE photometry. The 3D reddening map of Gontcharov provides both the minimal number of outliers bluer than any reasonable isochrone and the correct number of stars younger than 3Gyr in agreement with the Besancon Galaxy model. In another test Gaia DR1 TGAS parallaxes, Tycho-2 photometry and reddening/extinction estimates from nine data sources for 38,074 giants within 415pc from the Sun are used to compare their position in the Hertzsprung-Russell diagram with theoretical estimates, which are based on the PARSEC and MIST isochrones and the TRILEGAL model of the Galaxy with its parameters being widely varied. We conclude that, again, the estimates from the 3D reddening map of Gontcharov, including the median reddening E(B-V)=0.06mag at |b|>50{deg}, give the best fit of the empirical and theoretical data with each other. Based on these studies we present here the best up-to-date reddening, extinction and extinction-to-reddening estimates for the Gaia DR1 TGAS and Hipparcos stars within 415pc from the Sun. The accuracy of the E(B-V) estimates is proved to be better than 0.04mag everywhere in this space.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/2025
- Title:
- HIPASS-ZoA HII regions
- Short Name:
- J/MNRAS/450/2025
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Radio Recombination Line (RRL) survey of the Galactic plane from the Hi Parkes All-sky Survey and associated Zone of Avoidance survey, which mapped the region l=196{deg}-0{deg}-52{deg} and |b|<=5{deg} at 1.4GHz and 14.4-arcmin resolution. We combine three RRLs, H168{alpha}, H167{alpha}, and H166{alpha} to derive fully sampled maps of the diffuse ionized emission along the inner Galactic plane. The velocity information, at a resolution of 20km/s, allows us to study the spatial distribution of the ionized gas and compare it with that of the molecular gas, as traced by CO. The longitude-velocity diagram shows that the RRL emission is mostly associated with CO gas from the molecular ring and is concentrated within the inner 30{deg} of longitude. A map of the free-free emission in this region of the Galaxy is derived from the line-integrated RRL emission, assuming an electron temperature gradient with Galactocentric radius of 496+/-100K/kpc. Based on the thermal continuum map, we extracted a catalogue of 317 compact (<~15-arcmin) sources, with flux densities, sizes, and velocities. We report the first RRL observations of the southern ionized lobe in the Galactic Centre. The line profiles and velocities suggest that this degree-scale structure is in rotation. We also present new evidence of diffuse ionized gas in the 3-kpc arm. Helium and carbon RRLs are detected in this survey. The He line is mostly observed towards HII regions, whereas the C line is also detected further away from the source of ionization. These data represent the first observations of diffuse C RRLs in the Galactic plane at a frequency of 1.4GHz.
- ID:
- ivo://CDS.VizieR/J/A+A/594/A116
- Title:
- HI4PI spectra and column density maps
- Short Name:
- J/A+A/594/A116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Measurement of the Galactic neutral atomic hydrogen (HI) column density, NHI, and brightness temperatures, Tb, is of high scientific value for a broad range of astrophysical disciplines. In the past two decades, one of the most-used legacy HI datasets has been the Leiden/Argentine/Bonn Survey (LAB). We release the HI 4-pi survey (HI4PI), an all-sky database of Galactic HI, which supersedes the LAB survey. The HI4PI survey is based on data from the recently completed first coverage of the Effelsberg-Bonn HI Survey (EBHIS) and from the third revision of the Galactic All-Sky Survey (GASS). EBHIS and GASS share similar angular resolution and match well in sensitivity. Combining both, they are ideally suited to be a successor to LAB. The new HI4PI survey outperforms the LAB in angular resolution (16.1', FWHM) and sensitivity (43mK RMS). Moreover, it has full spatial sampling and thus overcomes a major issue of LAB, which severely undersamples the sky. We publish all-sky column density maps of the neutral atomic hydrogen in the Milky Way, along with full spectroscopic data, in several map projections including HEALPix.
- ID:
- ivo://CDS.VizieR/J/A+A/550/A23
- Title:
- HI shells in Leiden/Argentina/Bonn HI survey
- Short Name:
- J/A+A/550/A23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse the all-sky Leiden/Argentina/Bonn HI survey, where we identify shells belonging to the Milky Way. We used an identification method based on the search of continuous regions of a low brightness temperature that are compatible with given properties of HI shells. We found 333 shells in the whole Galaxy. The size distribution of shells in the outer Galaxy is fitted by a power law with the coefficient of 2.6 corresponding to the index 1.8 in the distribution of energy sources. Their surface density decreases exponentially with a scale length of 2.8kpc. The surface density of shells with radii >100pc in the solar neighbourhood is around 4 per kpc^2^ and the 2D porosity is around 0.7.
- ID:
- ivo://CDS.VizieR/J/A+A/437/101
- Title:
- HI shells in the outer Milky Way
- Short Name:
- J/A+A/437/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a method for an automatic search for HI shells in 3D data cubes and apply it to the Leiden-Dwingeloo HI survey of the northern Milky Way. In the 2nd Galactic quadrant, where identifications of structures are not substantially influenced by overlapping, we find nearly 300 structures.
- ID:
- ivo://CDS.VizieR/J/MNRAS/470/1462
- Title:
- HOPS. III. Dense molecular gas properties
- Short Name:
- J/MNRAS/470/1462
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The H_2_O Southern Galactic Plane Survey (HOPS) has mapped 100deg^2^ of the Galactic plane for water masers and thermal molecular line emission using the 22m Mopra telescope. We describe the automated spectral-line fitting pipelines used to determine the properties of emission detected in HOPS data cubes, and use these to derive the physical and kinematic properties of gas in the survey. A combination of the angular resolution, sensitivity, velocity resolution and high critical density of lines targeted make the HOPS data cubes ideally suited to finding precursor clouds to the most massive and dense stellar clusters in the Galaxy. We compile a list of the most massive HOPS ammonia regions and investigate whether any may be young massive cluster progenitor gas clouds. HOPS is also ideally suited to trace the flows of dense gas in the Galactic Centre. We find the kinematic structure of gas within the inner 500pc of the Galaxy is consistent with recent predictions for the dynamical evolution of gas flows in the centre of the Milky Way. We confirm a recent finding that the dense gas in the inner 100pc has an oscillatory kinematic structure with characteristic length-scale of 20pc, and also identify similar oscillatory kinematic structure in the gas at radii larger than 100pc. Finally, we make all of the above fits and the remaining HOPS data cubes across the 100deg^2^ of the survey available to the community.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/1764
- Title:
- H_2_O Southern Galactic Plane Survey (HOPS)
- Short Name:
- J/MNRAS/416/1764
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present first results of the H_2_O Southern Galactic Plane Survey (HOPS), using the Mopra Radio Telescope with a broad-band backend and a beam size of about 2arcmin. We have observed 100deg^2^ of the southern Galactic plane at 12mm (19.5-27.5GHz), including spectral line emission from H_2_O masers, multiple metastable transitions of ammonia, cyanoacetylene, methanol and radio recombination lines. In this paper, we report on the characteristics of the survey and H2O maser emission. We find 540 H_2_O masers, of which 334 are new detections.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/1972
- Title:
- H_2_O Southern Galactic Plane Survey, HOPS. II
- Short Name:
- J/MNRAS/426/1972
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The H2O Southern Galactic Plane Survey (HOPS) has mapped a 100{deg} strip of the Galactic plane (-70{deg}>l>30{deg}, |b|<0.5{deg}) using the 22m Mopra antenna at 12mm wavelengths. Observations were conducted in on-the-fly mode using the Mopra spectrometer (MOPS), targeting water masers, thermal molecular emission and radio-recombination lines. Foremost among the thermal lines are the 23GHz transitions of NH3 J,K=(1,1) and (2,2), which trace the densest parts of molecular clouds (n>10^4^cm^-3^). In this paper, we present the NH_3_(1,1) and (2,2) data, which have a resolution of 2arcmin and cover a velocity range of +/-200km/s.
- ID:
- ivo://CDS.VizieR/I/339
- Title:
- Hot Stuff for One Year (HSOY)
- Short Name:
- I/339
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recently, the first installment of data from ESA's Gaia astrometric satellite mission (Gaia DR1) was released, containing positions of more than 1 billion stars with unprecedented precision, as well as proper motions and parallaxes, however only for a subset of 2 million objects. The second release will include those quantities for most objects. In order to provide a dataset that bridges the time gap between the Gaia DR1 and Gaia DR2 releases and partly remedies the lack of proper motions in the former, HSOY ("Hot Stuff for One Year") was created as a hybrid catalog between Gaia and ground-based astrometry, featuring proper motions (but no parallaxes) for a large fraction of the DR1 objects. While not attempting to compete with future Gaia releases in terms of data quality or number of objects, the aim of HSOY is to provide improved proper motions partly based on Gaia data, allowing studies to be carried out just now or as pilot studies for later projects requiring higher-precision data. The HSOY catalog was compiled using the positions taken from Gaia DR1 combined with the input data from the PPMXL catalog, employing the same weighted least-squares technique that was used to assemble the PPMXL catalog itself. This effect resulted in a four-parameter astrometric catalog containing 583 million stars, with Gaia DR1 quality positions and proper motions with precisions from far less than 1 mas/yr to 5 mas/yr, depending on object brightness and location on the sky.
- ID:
- ivo://CDS.VizieR/J/A+A/635/A66
- Title:
- Humps and bumps in RR Lyrae stars
- Short Name:
- J/A+A/635/A66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the most extended and homogeneous study carried out so far of the main and early shocks in 1485 RR Lyrae stars in the Galactic bulge observed by the Optical Gravitational Lensing Experiment (OGLE). We selected nonmodulated fundamental-mode RR Lyrae stars with good-quality photometry. Using a self- developed method, we determined the centers and strengths of main and early shock features in the phased light curves. We found that the positions of both humps and bumps are highly correlated with the pulsation properties of the studied variables. Pulsators with a pronounced main shock are concentrated in the low-amplitude regime of the period-amplitude diagram, while stars with a strong early shock have average and above-average pulsation amplitudes. A connection between the main and early shocks and the Fourier coefficients is also observed. In the color-magnitude diagram (CMD), we see a separation between stars with strong and weak shocks. Variables with a pronounced main shock cluster close to the fundamental red edge of the instability strip (IS), while stars with a strong early shock tend to clump in the center and near the fundamental blue edge of the IS. The appearance of shocks and their properties appear to be independent of the direction of evolution estimated from the period change rate of the studied stars. In addition, the differences in the period change rate between the two main Oosterhoff groups found in the Galactic bulge suggest that stars of Oosterhoff type I are located close to the zero-age horizontal branch while Oosterhoff type II variables are on their way toward the fundamental red edge of the instability strip, and have therefore already left the zero-age horizontal branch.
